A vehicle headlamp using semiconductor light emitting elements such as LEDs (Light Emitting Diodes) has been known. The vehicle headlamp needs to form a certain light distribution pattern from the viewpoint of safety or the like.
Further, a sufficient amount of light has to be secured in the vehicle headlamp. For this reason, it is studied that a plurality of semiconductor light emitting elements are used in the vehicle headlamp. For example, Patent Document 1 discloses a vehicle headlamp using a light source module including a plurality of semiconductor light emitting elements. The semiconductor light emitting elements are electrically connected in series, have substantially the same light emitting area, and are disposed in a straight line.    [Patent Document 1] JP-A-2005-294166